What’s the secret to better to-do lists?

A well-maintained list is “an essential tool for staying grounded, for saving your energy and for doing things rather than trying to remember what to do,” says Julie Morgenstern, a New York author and expert on time management.

A list should reflect a time estimate needed for each task. And it should be integrated into a calendar or schedule, to avoid “planning 17 things for tomorrow which, if you added them up, are going to take 20 hours,” Ms. Morgenstern says.